1. Field of the Invention
The present invention relates generally to recovery systems used for recovery of a target drone. More particularly, the present invention relates to a precision parachute used in the recovery of a drone target which substantially reduces the possibility of damage to the target drone.
2. Description of the Prior Art
For many years, parachutes have been used for the flight and recovery stage of spacecraft, target drones, camera film and similar items. A problem with ordinary parachutes, which may be circular or conical in design, is that they descend almost vertically through the airstream and are generally carried with the prevailing winds and air currents. This leads to uncertainty as to the landing point. The landing point may be, for example, in rugged and remote mountainous terrain which is difficult or even impossible to reach for retrieval aircraft such as a helicopter.
In addition, the rate of descent of these parachutes is generally in the order of fifteen to twenty-five feet per second. The result may be a rough landing on a solid surface which could lead to damage to the payload the parachute is attached to. When, for example, the payload is a target drone and the target drone is damaged during a rough landing, the cost to repair the target drone can be significant. In addition, the target drone can be totally destroyed during an extremely rough landing, which can result in a loss of several hundred thousand dollars to the military. For example, the BQM-34 aerial target cost the military about half million dollars.
Landings are often conducted on water to avoid rough landings. These water landings involve other complexities, such as auxiliary flotation devices, to keep the payload from sinking. These water landings also require that the payloads be of a type that cannot be damaged by water and be of the type that are protected against water damage.
Ram-air inflated parachutes, such as those used by sports sky divers, are able to move horizontally as much as three or four feet for every foot of vertical descent. This allows the parachutes to make headway into a fairly stiff wind of up to twenty or thirty knots.
However, a pilot is required to steer these ram-air inflated parachutes to the selected landing point. Specifically, Ram-air inflated parachutes are steered by pulling down on a pair of steering toggles which lower trailing edge flaps at the rear of the canopy. Pulling down on the right flap steers the canopy to the right and pulling down on the left flap steers the canopy to the left. Pulling on both flaps simultaneously results in a flair which reduces forward speed and vertical descent rate for a short period of time. This allows for a much more precise and gentle touchdown and landing than a parachute of conventional design.
Since a pilot is required for the use of ram-air inflated parachutes to land a payload for the purpose of recovering the payload, ram-air inflated parachutes are not the optimal choice for use in the recovery of a payload such as a target drone.
It is preferable that a parachute operate in a manner similar to a ram-air inflated parachute but not require the use of a pilot to steer the parachute.
The present invention overcomes some of the disadvantages of the prior art including those mentioned above in that it comprises a relatively simple yet highly effective precision parachute recovery system which provides for the recovery of a payload such as a target drone without damage by allowing for a safe, non-destructive landing of the payload at a desired location.
The parachute recovery system of the present invention comprises a payload, a parachute or parasail and a guidance control electronics and servo system. The parachute, which is rectangular in shape, is connected by a plurality of control lines to the guidance control electronics and servo system, which is attached to the payload. The payload may be an air launch component such as a spacecraft, a target drone, an unmanned air vehicle, camera film, or similar apparatus.
The guidance control electronics and servo system is used to control glide path trajectory and provide for a safe non-destructive landing of the payload. The servo system adjusts the length of each of the plurality of control lines attached to the parachute to provide a means for controlling the parachute so as to control the speed, direction and lift of the parachute recovery system.
An antenna and its associated GPS receiver receives GPS data from a transmitting station. The GPS data may include longitude, latitude and altitude data as well as rate of descent data which the guidance control electronics and servo system processes to steer the precision recovery system to a precise location and to control the rate of descent of the recovery system allowing for a gentle touchdown and soft landing of the payload. The guidance control electronics and servo system includes a guidance control device/digital computer and a plurality of servos each servo of which adjust the length of one of the control lines to steer the parachute recovery system to a safe non-destructive landing of the payload.
The parachute recovery system also includes an inertial navigation unit, a remote control unit a preprogrammed target landing area coordinates unit and a beacon connected to the guidance control device. The inertial navigation unit provides payload position data to the guidance control device and may be used may with the GPS receiver, in place of the GPS receiver or as a backup to the GPS receiver. The remote control unit sends servo/guidance commands to the guidance control unit for flight path control of parachute recovery system and may be used in conjunction or as an alternative to the GPS receiver and inertial navigation unit. The preprogrammed target landing area coordinates unit supplies preprogrammed target landing coordinates for the parachute recovery system to the guidance control device and may be used for autonomous guidance without the use of the remote control unit. The beacon sends payload position data to a remote receiving station and may be used for feedback to the remote control unit, to provide payload position data to recovery crews or it may be deactivated for covert operations.